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G. H. DUTHIE.

STEAM VALVE. No. 346,434. PatentedJuly 27, 1886.

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UNITED STATES BarnN'r @Phrea GEORGE H. DUTHIE, OF MUSKEGON, MICHIGAN, ASSIGNOR OF OND-HALF TO IV. V. BARCUS, OF SAME PLACE.

STEAM-VALVE.

SPECIFICATION forming part of Letters Patent No. 346,434, dated -Itfy 27, 1886.

Applfeatien lilexl Sepletnherl, 1885. Serial No. ljifl. (No modul.)

T @ZZ wtom it may concern:

Be it known that I, GEORGE II. DU'rI-HE, of Muskegon, in the county of Muskegon and State of Michigan, have invented certain new and useful Improvements in Steam-Valves; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference heilig had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this speeieation.

The object of my invention is to provide a new and improved oscillating valve for the cylinders of steam-engines, the action of which is balanced and equable by reason of the construction thereof, which equalizcs the pressure ef the live steam within the valve-chamber, substantially as hereinafter described, and as illustrated in the drawings, in which- Figure lis a longitudinal vertical section of my invention. Fig. 2 is a transverse vertical section thereof. Fig. 3 is a detail view, and Figs. 4 and 5 are detail views illustrating` the action of the valve.

Reference being had tothe drawings, A represents a cylinder having a piston and a piston-head, I3, therein, and having the steamvalve-chamber C, which is placed transversely on said cylinder at its center of length.

Running longitudinally and centrally under and open to chamber G midwaybetween steamports e and b is the exhaust-port c. rIhe width of the opening of this exhaust-port is j ust about twice that of either steam-port, and the exhaust-pipe leads from one end thereof laterally to the cylinder, as shown in Fig. 2.

The interior of the valve-chamber is cylindrical, and slightly tapers from the end thereof to which the steam-supply pipe is connected to the opposite end, and in it is placed the oscillating valve D, which is of a shape corresponding to the interior of the valve-chamber, but not of the same length, so that as the engaging surfaces of the valve and valve-chamber wear away the valve may be adj usted longitudinally (by means to be described further 5o on) to take up the wear.

ports a and b leading from either end of the' Valve D is fast or permanently secured to the valve-shaft, which, as will be observed, has its bearings in the outer wall ol' the steamsupply pipe and smaller end of the val ve-chamber suitably packed to prevent the steam eseaping, and has its ends extended beyond its bearings. The end of this shaft contiguous to the supply-pipe has a crank or other means attachedthercto, through the medium of which the valve is given a positive oscillating mo- 6o tion. rlhe other end is stepped to a smaller diameter, and said stepped portion passes through a sleeve and has a head or boss on its extremity. The sleeve referred to has its cirleumfercnee screw-threaded, and has an annular ange on its end adjacent to the head of the shaft, the periphery of which is polygonal, so that a wrench could be made to obtain a purchase thereon, to move said sleeve longitudinall y within the correspondingly-serew- 7o threaded aperture in the extremity of an arm, c, which is secured to and projects from the adjacent end of the valve-chamber.

rlhe valve D is hollow and open at both ends. It is provided with a longitudinal exhaustchamber, E, made by depressing the periphery of the valve, the width of which corresponds to the distance from one edge of the exhaustport to the farther edge of the steam-port farthest from said edge. Located on either side So of this exhaust-chamber E, a distance removed therefrom equal to the distance from one edge of the exhaust-port to the farthest edge of the nearest steam-port, are the longitudinal openings G and F. S5

The operation of my invention is as follows: Say, the valve and piston-head are in the position shown in Fig. 1. lIhis is the first position. As the valve oscillates in the direction ofthe arrow, thepiston will travel toward theleft-hand go end of the cylinder. \Vhen the valve reaches the position shown in Fig. 4, the piston-head will have reached the left-hand end ofthe cylinder, and will reverse its motion and be forced by the expansion of the steam toward the other end as the opening G gradually assumes the position shown in Fig. 5. Then in about the position shown in Fig. 5, the valve reverses its motion, and the return oscillation drives the piston-head back toward the other end of the io) steam, but for the purpose of equalizing the area of the inside of the valve-fin other words,

to offset the openings G and F, and thus make a balanee-valve.

A very important feature of my invention is, that the valve may be fed with live steam from either end, or, if desired, from both ends. This latter construction would'be especially desirable when the valve is used on locomotives.

l. The combination, with a hollow oscillat- .ing valve having the longitudinal openings G- and F and the balance openings gg, arranged diametrieally opposite thereto, and the eX- hanst-ehamber E, of the steameyli`nder A, having the steam-ports a and b and the exhaust-port c, opening into said valve-chamber z5 and the piston andpiston-head.

2. The combination, with hollow oscillating valve open at both ends, having openings G and F and exhaust-chamber E, cylinder A, having steam and exhaust ports a, b, and c, of 3o the valve-chamber C, having its interior corresponding to the shape of said valve, and having a steam-supply pipe opening into one end thereof, substantially as and for the purpose set forth.

In testimony that I. claim the foregoing as my own I hereunto affix my signaturein presenee of two witnesses.

GEORGE H. DUTHIE.

W`i tnesses JAMEs H. CoYNE, FRANK D. THOMASON. 

